Alonistaina (Greek: Αλωνίσταινα) is a mountain village in the municipal unit of Falanthos, Arcadia, Greece. It is situated in the forested northern Mainalo mountains, at about 1200 m elevation, making it one of the highest villages in the Peloponnese. It is 6 km north of Piana, 6 km southeast of Vytina, 9 km southwest of Levidi and 18 km northwest of Tripoli.